Exit and Disposal Costs - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring And Related Activities [Abstract]
Severance expense	$ 13	$ 76	$ 252
Accrued severance costs paid	57	170	81
Exit related costs	15	65	220
Accrued facility and other exit costs paid	21	158	$ 102
Accrued exit related costs	19	25
Accrued severance costs	$ 33	$ 77
Expected period for all payments for severance cost	2016
Expected period for all payments for facility and exit cost	Pay through 2027